共查询到20条相似文献,搜索用时 31 毫秒
1.
A.A. Mamun 《Physics letters. A》2008,372(6):884-887
An adiabatic hot dusty plasma (containing non-inertial adiabatic electron and ion fluids, and negatively charged inertial adiabatic dust fluid) is considered. The basic properties of arbitrary amplitude dust-acoustic (DA) solitary waves, which exist in such an adiabatic hot dusty plasma, are explicitly examined by the pseudo-potential approach. To compare the basic properties (critical Mach number, amplitude and width) of the DA solitary waves observed in a dusty plasma containing adiabatic electron, ion and dust fluids with those observed in a dusty plasma containing isothermal electron and ion fluids and adiabatic dust fluid, it has been found that the adiabatic effect of inertia-less electron and ion fluids has significantly modified the basic properties of the DA solitary waves, and that on the basic properties of the DA solitary waves, the adiabatic effect of electron and ion fluids is much more significant than that of the dust fluid. 相似文献
2.
Properties of nonplanar (viz. cylindrical and spherical) dust ion-acoustic (DIA) solitary and shock waves propagating in a dusty plasma containing charge fluctuating stationary dust, inertial warm ions, and non-isothermal electrons following a vortex-like distribution, are investigated by the reductive perturbation method. It has been shown that all the basic features of the DIA solitary and shock waves are significantly modified by the effects of vortex-like electron distribution, dust charge fluctuation, and nonplanar cylindrical and spherical geometries. The implications of our results in some space and laboratory dusty plasma environments are briefly discussed. 相似文献
3.
H. Alinejad 《Physics letters. A》2009,373(33):2935-2939
The effect of deviations from isothermality of ions on arbitrary amplitude dust-acoustic solitary structures is studied in an unmagnetized dusty plasma which consists of a negative charged dust fluid, free electrons and hot ions obeying a trapped distribution. For the finite deviation from isothermality of ions, the basic properties of large amplitude solitary waves are studied by employing pseudo-potential approach. It is shown that the effect of such ion behavior changes the maximum values of the Mach number and the amplitude for which solitary wave can exist. For the case that the deviation from isothermality due to nonlinear resonant particle effects is small, calculations by reductive perturbation method leads to a generalized Korteweg-de Vries equation with mixed nonlinearity. The latter admits a stationary dust-acoustic solitary solution with similar width and qualitatively different amplitude in comparison to the case that deviations from isothermality are finite. Furthermore, effects of the equilibrium free electron density and such trapped ions on the amplitude of solitary structures imply a non-uniform transition from the Boltzmann ion distribution to the trapped ion one. 相似文献
4.
A.A. Mamun 《Physics letters. A》2008,372(9):1490-1493
The nonlinear propagation of dust-ion-acoustic (DIA) waves in an adiabatic dusty plasma (containing adiabatic inertial-less electrons, adiabatic inertial ions, and negatively charged static dust) is investigated by the pseudo-potential approach. The combined effects of adiabatic electrons and negatively charged static dust on the basic properties (critical Mach number, amplitude, and width) of small as well as arbitrary amplitude DIA solitary waves are explicitly examined. It is found that the combined effects of adiabatic electrons and negatively charged static dust significantly modify the basic properties (critical Mach number, amplitude, and width) of the DIA solitary waves. It is also found that due to the effect of adiabaticity of electrons, negative DIA solitary waves [which are found to exist in a dusty plasma (containing isothermal electrons, cold ions, and negatively charged static dust) for α=zdnd0/ni0>2/3, where zd is the number of electrons residing onto a dust grain surface, nd0 is the constant (static) dust number density and ni0 is the equilibrium ion number density] disappears, i.e. due to the effect of adiabatic electrons, one cannot have negative DIA solitary waves for any possible set of dusty plasma parameters [0?α<1 and 0?σ=Ti0/Te0?1, where Ti0 (Te0) is electron (ion) temperature at equilibrium]. 相似文献
5.
The effects of nonadiabatic dust charge fluctuation on the nonlinear propagation of the dust acoustic (DA) solitary wave in collisionless dusty plasma with streaming ions have been investigated. By using the reductive perturbation technique, a modified Korteweg-de Vries (mKdV) equation governing the nonlinear waves was derived and the solitary solution of the mKdV equation was also obtained. It was shown that the damping rate of the slow mode DA solitary wave was strongly affected by the ion streaming velocity. 相似文献
6.
The nonlinear propagation of small amplitude dust‐acoustic (DA) solitary waves in magnetized dusty plasma consisting of negatively charged mobile dust fluid, and Boltzmann‐distributed electrons and ions with two distinct temperatures following a q‐nonextensive distribution are investigated. In this article, a number of nonlinear equations, namely, the Korteweg–de‐Vries (K‐dV) equations, have been derived by employing the reductive perturbation technique that is valid for a small but finite amplitude limit. The effects of nonextensivity of ions with two distinct temperatures and dust concentration on the amplitude and width of DA solitary waves are investigated theoretically. It is observed that both the nonextensive and low‐temperatures ions significantly modify the basic properties and polarities of DA solitary waves. It is shown that both positive and negative potential DA solitons occur in this case. The implications of these results to some astrophysical environments and space plasmas (e.g., stellar polytropes, peculiar velocity distributions of galaxies, and collisionless thermal plasma), and laboratory dusty plasma systems are briefly mentioned. 相似文献
7.
The nonlinear propagation of ultra-low-frequency dust-acoustic (DA) waves in a strongly coupled cryogenic dusty plasma has been investigated, by using the Boltzmann distributed electrons and ions, as well as modified hydrodynamic equations for strongly coupled charged dust grains. The reductive perturbation technique is used to derive the Burger equation. It is shown that strong correlations among negatively charged dust particles acts like a dissipation, which is responsible for the formation of the DA shock waves. The latter are associated with the negative potential, i.e. with the compression of negatively charged cryogenic dust particle density. It is also found that the effective dust-temperature, which arises from electrostatic interactions among negatively charged dust particles, significantly affects the height of the DA shock structures. New laboratory experiments at cryogenic temperature should be conducted to verify our theoretical prediction. 相似文献
8.
A dusty multi-ion plasma system consisting of non-isothermal (trapped) electrons, Maxwellian (isothermal) light positive ions,
warm heavy negative ions and extremely massive charge fluctuating stationary dust have been considered. The dust-ion-acoustic
solitary and shock waves associated with negative ion dynamics, Maxwellian (isothermal) positive ions, trapped electrons and
charge fluctuating stationary dust have been investigated by employing the reductive perturbation method. The basic features
of such dust-ion-acoustic solitary and shock waves have been identified. The implications of our findings in space and laboratory
dusty multi-ion plasmas are discussed. 相似文献
9.
A.A. Mamun A.A. Gebreel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,10(2):301-305
A theoretical investigation has been made of nonlinear propagation of ultra-low-frequency electromagnetic waves in a magnetized
two fluid (negatively charged dust and positively charged ion fluids) dusty plasma. These are modified Alfvén waves for small
value of and are modified magnetosonic waves for large , where is the angle between the directions of the external magnetic field and the wave propagation. A nonlinear evolution equation
for the wave magnetic field, which is known as Korteweg de Vries (K-dV) equation and which admits a stationary solitary wave
solution, is derived by the reductive perturbation method. The effects of external magnetic field and dust characteristics
on the amplitude and the width of these solitary structures are examined. The implications of these results to some space
and astrophysical plasma systems, especially to planetary ring-systems, are briefly mentioned.
Received 8 July 1999 and Received in final form 11 October 1999 相似文献
10.
ABSTRACT In framework of the extended Poincaré–Lighthill–Kuo, the properties of dust acoustic (DA) solitary wave’s interaction are investigated in four-component quantum dusty plasma. Two Korteweg–de Vries equations describing the colliding DA solitary waves are derived by eliminating the secularities. By knowing the explicit form of the solitary wave solutions, the leading phase changes, trajectories and phase shifts are obtained, accordingly. The effects of various physical parameters such as the quantum mechanical parameters, the charge ratio between positive and negative dust particles, the mass ratio between negative and positive dust particles and the ratio of electron to ion temperatures are studied extensively. Our findings showed that these parameters play a significant role on the characteristics and basic features of DA solitary waves such as phase shifts in trajectories due to collision. The obtained results may be beneficial to understand well the collision of DA solitary waves that may occur in laboratory plasmas, space plasma as well as in plasma applications. 相似文献
11.
Effect of dust charge variation on dust—acoustic solitary waves in a magnetized two—ion—temperature dusty plasma
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The effect of dust charge variation on the dust-acoustic solitary structures is investigated in a warm magnetized two-ion-temperature dusty plasma consisting of a negatively and variably charged extremely massive dust fluid and ions of two different temperatures. It is shown that the dust charge variation as well as the presence of a second component of ions would modify the properties of the dust-acoustic solitary structures and may exite both dust-acoustic solitary holes (soliton waves with a density dip) and positive solitons (soliton waves with a density hump). 相似文献
12.
Smain Younsi 《Physics letters. A》2008,372(31):5181-5188
The problem of nonlinear variable charge dust acoustic waves in a dusty plasma with trapped ions is revisited. The correct non-isothermal ion charging current is presented for the first time based on the orbit motion limited (OML) approach. The variable dust charge is then expressed in terms of the Lambert function and we take advantage of this new transcendental function to investigate nonlinear localized dust acoustic waves in a charge varying dusty plasma with trapped ions more rigorously. 相似文献
13.
Effect of nonthermal ion distribution and dust temperature on nonlinear dust-acoustic solitary waves
Dust-acoustic solitary waves in unmagnetized dusty plasma whose constituents are inertial charged dust grains, Boltzmannian
electrons and nonthermal ions have been investigated by taking into account finite dust temperature. The pseudopotential has
been used to study solitary solution. The existence of solitary waves having negative potential is reported. 相似文献
14.
B. Sen B. Das P. Chatterjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(2):211-216
Nonlinear dust acoustic solitary waves in a dusty plasma are studied for nonzero kinematic viscosity. Sagdeev’s potential
can be obtain upto any order in ϕ. The existence of soliton solution is determined by pseudopotential approach. It is seen
that the electron inertia has a significant effect on the existence of solitary waves in presence of kinematic viscosity. 相似文献
15.
A.A. Mamun A.A. Gebreel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):473-480
A theoretical investigation has been made of ultra-low-frequency dust-electrostatic and dust-electromagnetic modes, propagating
perpendicular to the external magnetic field, in a self-gravitating, warm, magnetized, two fluid dusty plasma system. It has
been shown that the effects of self-gravitational field and dust thermal pressure significantly modify the dispersion properties
of these ultra-low-frequency dust-modes. It is also found that under certain conditions, the self-gravitational effect can
destabilize these ultra-low-frequency dust-electrostatic and dust-electromagnetic modes. However, the effects of the external
magnetic field and dust and ion thermal pressures are found to play stabilizing role, i.e., these effects make these modes stable and counter the gravitational condensation of the dust grains. The implications of
these results to some space and astrophysical dusty plasma systems, especially, to planetary ring-systems and cometary tails,
are briefly mentioned.
Received 16 December 1999 相似文献
16.
Large-amplitude dust acoustic solitons in an opposite polarity dusty plasma with generalized polarization force
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Linear and nonlinear dust acoustic(DA)waves have been investigated in an opposite polarity dusty plasma comprising negatively and positively charged dust grains,Maxwellian electrons and ions,including the generalized polarization force effect.The properties of linear DA waves have been significantly altered by the dual dust polarity and polarization force.Large amplitude DA solitons have been discussed in the framework of the Sagdeev potential technique.Our results show that both rarefactive and compressive solitons can exist in such a dusty plasma.The basic features of the Sagdeev potential have been examined under the effect of the polarization force parameter R,the ratio of the charge number of the positive dust to that of the negative dust Z,and the Mach number M.The results show that these parameters play a significant role in determining the region of existence of large amplitude DA solitons. 相似文献
17.
Modulational instability of dust acoustic waves in a dusty plasma with nonthermal electrons and ions
A. P. Misra A. Roy Chowdhury 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(1):49-57
Effects of nonadiabaticity of variable dust charge, dust fluid temperature, trapped electrons as well as nonisothermality
of ions on the amplitude modulation of dust acoustic waves in an unmagnetized dusty plasma are investigated. A modified nonlinear
Schr?dinger equation (NLSE) is obtained by the standard reductive perturbation technique and is solved numerically by the
split-step Fourier method. The modulational instability and the envelope solitary wave structure are found to be modified
somewhat by the effects of nonthermally distributed ions and trapped electrons. 相似文献
18.
19.
A.A. Mamun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(1):143-147
An investigation has been made of ion-acoustic solitary waves in an unmagnetized nonthermal plasma whose constituents are
an inertial ion fluid and nonthermally distributed electrons. The properties of stationary solitary structures are briefly
studied by the pseudo-potential approach, which is valid for arbitrary amplitude waves, and by the reductive perturbation
method which is valid for small but finite amplitude limit. The time evolution of both compressive and rarefactive solitary
waves, which are found to coexist in this nonthermal plasma model, is also examined by solving numerically the full set of
fluid equations. The temporal behaviour of positive (compressive) solitary waves is found to be typical, i.e., the positive initial disturbance breaks up into a series of solitary waves with the largest in front. However, the behaviour
of negative (rarefactive) solitary waves is quite different. These waves appear to be unstable and produce positive solitary
waves at a later time. The relevancy of this investigation to observations in the magnetosphere of density depressions is
briefly pointed out.
Received 12 October 1999 相似文献
20.
The dispersion relation of the dust-lower-hybrid wave has been derived using the quantum hydrodynamic model of plasmas in an ultracold Fermi dusty plasma in the presence of a uniform external magnetic field. The dust dynamics, electron Fermi temperature effect, and the quantum corrections give rise to significant effects on the dust-lower-hybrid wave of the magnetized quantum dusty plasmas. 相似文献